Androd学习笔记——[转]Android Http get post请求

首先我们先了解下Get请求和Post请求的区别：

表单提交中get和 post方式的区别有5点：
1.get是从服务器上获取数据，post是向服务器传送数据。
2.get是把参数数据队列加到提交表单的 ACTION属性所指的URL中，值和表单内各个字段一一对应，在URL中可以看到。post是通过HTTPpost机制，将表单内各个字段与其内容放置在HTML HEADER内一起传送到ACTION属性所指的URL地址。用户看不到这个过程。
3.对于get方式，服务器端用 Request.QueryString获取变量的值，对于post方式，服务器端用Request.Form获取提交的数据。
4.get 传送的数据量较小，不能大于2KB。post传送的数据量较大，一般被默认为不受限制。但理论上，IIS4中最大量为80KB，IIS5中为100KB。
5.get安全性非常低，post安全性较高。

一、HttpClinet方式

1、HTTP GET 示例:

public class TestHttpGetMethod{  
    public void get(){  
        BufferedReader in = null;  
        try{  
            HttpClient client = new DefaultHttpClient();  
            HttpGet request = new HttpGet();  
            request.setURI("http://w26.javaeye.com");  
            HttpResponse response = client.execute(request);   
            in = new BufferedReader(new InputStreamReader(response.getEntity().getContent()));     
            StringBuffer sb = new StringBuffer("");   
            String line = "";  
            String NL = System.getProperty("line.separator");  
            while((line = in.readLine()) != null){  
                sb.append(line + NL); 

            }  
            in.close();  
            String page = sb.toString();  
            Log.i(TAG, page);  
        }catch(Exception e){  
            Log.e(TAG,e.toString())  
        }finally{  
            if(in != null){  
                try{  
                    in.close();  
                }catch(IOException ioe){  
                    Log.e(TAG, ioe.toString());  
                }  
            }  
        }  
    }  
}

带参数的 HTTP GET:
HttpGet request = new HttpGet("http://www.baidu.com/s?wd=amos_tl"); 
client.execute(request);

2、HTTP POST 示例:

public class TestHttpPostMethod{  
    public void post(){  
        BufferedReader in = null;  
        try{  
            HttpClient client = new DefaultHttpClient();  
            HttpPost request = new HttpPost("http://localhost/upload.jsp");   
            List<NameValuePair> postParams = new ArrayList<NameValuePair>();  
            postParams.add(new BasicNameValuePair("filename", "sex.mov"));  
            UrlEncodeFormEntity formEntity = new UrlEncodeFormEntity(postParams);  
            request.setEntity(formEntity);  
            HttpResponse response = client.execute(request);  
            in = new BufferedReader(new InputStreamReader(response.getEntity().getContent()));     
            StringBuffer sb = new StringBuffer("");   
            String line = "";  
            String NL = System.getProperty("line.separator");  
            while((line = in.readLine()) != null){  
                sb.append(line + NL);  
            }  
            in.close();  
            String result = sb.toString();  
            Log.i(TAG, result );  
        }catch(Exception e){  
            Log.e(TAG,e.toString())  
        }finally{  
            if(in != null){  
                try{  
                    in.close();  
                }catch(IOException ioe){  
                    Log.e(TAG, ioe.toString());  
                }  
            }  
        }  
    } 
}

二、HttpURLConnection 方式

URL url = null;
HttpURLConnection conn = null;
InputStream in = null;
OutputStream out = null;
byte[] data ="测试字符串".getBytes();
try{
   url =new URL("www.xxx.com/servlet");
   conn = (HttpURLConnection) url.openConnection();

   //设置连接属性
   conn.setDoOutput(true);// 使用 URL 连接进行输出
   conn.setDoInput(true);// 使用 URL 连接进行输入
   conn.setUseCaches(false);// 忽略缓存
   conn.setConnectTimeout(30000);//设置连接超时时长，单位毫秒
   conn.setRequestMethod("POST");//设置请求方式，POST or GET，注意：如果请求地址为一个servlet地址的话必须设置成POST方式

//设置请求头
  conn.setRequestProperty("Accept", "*/*");
  conn.setRequestProperty("Connection", "Keep-Alive");
  conn.setRequestProperty("Accept-Charset", "utf-8");
  if (data != null) {
     out = conn.getOutputStream();
     out.write(data);
  }
  int code = conn.getResponseCode();
  if(code ==200){
     in = conn.getInputStream();// 可能造成阻塞
     long len = conn.getContentLength();
     byte[] bs = new byte[(int) len];//返回结果字节数组
     int all = 0;
  int dn = 0;
     while ((dn = in.read(bs, all, 1)) > 0) {
       all += dn;
       if (all == len) {
       break;
       }
     }
  }
}

 

======================================

那么接下来让我们看看在Android平台开发中如何执行一个Post请求：

以下是代码示例：

package com.jixuzou.search;
import java.util.ArrayList;
import java.util.List;
import org.apache.http.HttpResponse;
import org.apache.http.NameValuePair;
import org.apache.http.client.entity.UrlEncodedFormEntity;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.impl.client.DefaultHttpClient;
import org.apache.http.message.BasicNameValuePair;
import org.apache.http.protocol.HTTP;
import org.apache.http.util.EntityUtils;
import android.app.Activity;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
public class mian extends Activity {
        /** Called when the activity is first created. */
        private Button btnTest;
        @Override
        public void onCreate(Bundle savedInstanceState) {
                super.onCreate(savedInstanceState);
                setContentView(R.layout.main);
                btnTest = (Button) findViewById(R.id.Button01);
                btnTest.setOnClickListener(new OnClickListener() {
                        @Override
                        public void onClick(View v) {
                                getWeather();
                        }
                });
        }
        private void getWeather(){
                try {
                        final String SERVER_URL = "http://webservice.webxml.com.cn/WebServices/WeatherWS.asmx/getWeather"; // 定义需要获取的内容来源地址
                        HttpPost request = new HttpPost(SERVER_URL); // 根据内容来源地址创建一个Http请求
                        List params = new ArrayList();
                        params.add(new BasicNameValuePair("theCityCode", "长沙")); // 添加必须的参数
                        params.add(new BasicNameValuePair("theUserID", "")); // 添加必须的参数
                        request.setEntity(new UrlEncodedFormEntity(params, HTTP.UTF_8)); // 设置参数的编码
                        HttpResponse httpResponse = new DefaultHttpClient().execute(request); // 发送请求并获取反馈
// 解析返回的内容
                        if (httpResponse.getStatusLine().getStatusCode() != 404)
                        {
                                String result = EntityUtils.toString(httpResponse.getEntity());
                                System.out.println(result);
                        }
                } catch (Exception e) {
                }
        }
}